Engine starting apparatus



Dec. 29, 1936. I D 2,065,889

ENGINE STARTING APPARATUS Filed Aug. 16, 1933 2 q'lm' 1 6'4 l k I T0 IGNITION Patented Dec. 29, 1936 UNITED STATES ENGINE STARTING APPARATUS John B. Dyer, Pendleton, Ind., assignor, by mesne assignments, to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application August 16, 1933, Serial No. 685,315

4 Claims.

invention relates to starting apparatus for internal combustion engines and more particularly to those of automotive Vehicles.

Starting apparatus for internal combustion engines of the semi-automatic type, which includes a starting motor designed to be rendered operative upon the closing of the ignition switch and a second switch operable by some of the ordinary control devices of the vehicle such as the accelerator pedal or clutch pedal and rendered inoperative by engine suction when the engine is running under its own power is old, in which action of engine suction opens either the switch which is closed by the above mentioned vehicle control, or a separate switch in the starting motorcircuit, and an example of such apparatus is disclosed in applicant's copending application Serial No. 594,553, filed February 23, 1932.

In devices of this character which have already been designed, it has been found difiicult to provide a suction operated switch which is sufficiently sensitive to remain open under all operating conditions when the engine is running under its own power and which is not so sensitive as to be opened during the cranking of the engine by the starting motor. For instance, when the engine is under sufilciently heavy load with wide open throttle as when the vehicle is ascending a steep incline, the suction is very low and it has been diflicult to design a suction-controlled switch which will remain in open position under such circumstances and which will not open during engine cranking.

It is the principal object of the present invention to provide a suction-operated switch which will remain closed at all times during the cranking of the engine by the starting motor, but which will be held open by the engine suction under all conditions of speed and load when the engine is operating under its own power. According to the present invention, this object is accomplished by the provision of a diaphragm subject to engine suction and operative to effect the movement of the movable switch contact, which diaphragm is constructed of thin sheet metal such as spring steel and which is so designed that a considerable degree of suction is required to move the diaphragm from its switch closed position to switch open position, but-a very low degree of suction will be effective to hold the diaphragm in its switch open position after it has once been moved to such position.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

Fig. 1 is a wiring diagram present invention.

Fig. 2 is a detail, sectional view of a preferred form of the suction-controlled switch.

Fig. 3 is a fragmentary, detail view of a modified form of the suction-controlled switch.

Referring to Fig. 1, the starting motor I0 is 10 grounded at l2. As illustrated, this starting motor is adapted to drive the engine through the medium of the well-known Bendix drive (not shown). The motor I 0 is connected by wire l4 with one fixed contact it of a magnetic switch 15 indicated in its entirety by the letter A, while the other fixed contact I8 is connected by wire 20 with a wire 22 leading to a battery 24 grounded through the connection 26. Cooperating with the contacts l6 and I8 is a movable contact 28 20 carried by the armature 30 of a solenoid comprising a core 32 surrounded by winding 34, the movable contact being normally held in open position by a spring 36, while a housing 38 encloses the winding. When this magnetic switch is closed 5 current will flow from the battery through wires 22, 20, switch A, wire l4 to the starting motor, through the ground connection I! to ground and through ground connection 26 to the battery, thus causing the starting motor to operate.

The magnetic switch is adapted to be closed upon closing of the ignition switch and another switch indicated in its entirety by the letter B, which is adapted to be closed by the accelerator pedal which controls the quantity of fuel mixtime supplied by the carburetor to the engine. The magnetic switch is caused to open when the engine is running under its own power and is prevented from closing as long as the engine continues to run under its own power by the action of engine suction which operates the switch B and thus causes the magnet of said magnetic switch to be de-energized so that the magnetic switchwill remain open as long as the engine of one form of the suction remains sufflcient to hold the switch B open.

The winding of the magnetic switch; A is grounded by a wire 40 and the other end of the winding is connected by wire 42 to one of the fixed contacts 44 of the switch B, while the other fixed contact 46 of said switch is connected by a wire 48 with a wire 50 which leads from the fixed contact 52 of the ignition switch to the ignition system of the engine.- The movable contact 54 of the ignition switch is con- 5 diaphragm and the cooperating fiange on thenected by the wire 88 with the wire 22 which leads to the battery, as previously described. .The wire 22 is also connected by a wire 88 with a generator 82 which is grounded at 64 and is provided with the usual cut-out relay 88.

The circuit above described operates as follows. When the ignition switch 54 and the switch B, which is adapted to be closed by the accelerator pedal as hereinafter more specifically set forth, are both closed, current will flow from the battery which is grounded through the connection 26 through the wires 22 and, the ignition switch, wire 48, switch; B and wire 42 to the winding of the magnetic switch A and through the connection 48 to ground. This will energize-the magnetic switch A and cause the movable contact member 28 to be moved into engagement with the fixed contacts I6 and I8 at which time current will flow from the battery through the wires 22 and 28, contacts I8, 28, and I6 and wire I4 to the starting motor and through the connection I2 to ground. When the circuit of the starting motor is closed in this manner, the motor will become operative to start.

the engine and when the latter begins to run under its own power, the switch B will be opened by engine suction in a'manner more fully de-- scribed later. When this takes place, the circuit through the winding of the magnetic switch A will be broken, the magnet of such switch will be de-energized and the contact 28 will be out of engagement with contacts I6 and I8 to break the starting motor circuit and thus cause the starting motor to become inoperative.

The switch B comprises, in addition to the fixed contacts 44 and 48, a movable contact 68 which is shown in'Fig. 2 and 'is adapted to be rotated so as to be moved into engagement with the fixed contacts 44 and 48 by means of an arm 18, which is adapted to be connected in any suitable way to the accelerator pedal which regulates the quantity of fuel mixture supplied to the engine. The switch B comprises a sheet metal housing I2 which is supported by a suitable bracket mounted on the engine or in any desirable way. Riveted or otherwise secured to this housing is a diaphragm chamber formed of two cup-shaped sheet metal shells." and I8 suitably flanged and'joined together so as to form a fluid-tight joint with a diaphragm I8 secured between the flanges. As shown in the drawing,the metal shell I8 is provided with a flange which is pressed over the edge of the shell I4, as clearly shown in Fig; 2. The housing 12 is closed at one end by a circular block of insulating material 88 which supports the fixed contacts 44 and 48.

Secured to and supported atone end by the diaphragm I8 and extending through an opening 82 in the housing I2 is a cylindricalv element 84 which has a stud or spindle 88 projecting from its opposite end. 'Pivotally mounted on the stud 86 is the movable contact .member 68 previously referred to. This contact member has two arcuate contact surfaces 88 formed thereon.

which are adapted to be moved into contact with the fixed contacts 44 and 48 when the contact member 88 is rotated in the manner more specifically described later. The contact member 88 is held fiat against the closed end of the cylindrical member 84 by washers 98 and a looking clip 92 which engages a groove (notshown) in the stud 86. Posts 94 are secured in the housing l2-on opposite sides of the cylindrical member 84 and act as stops to limit the movements of the contact member 88, while a helical spring 96 is connected at one end to one 01 said posts and at the other end to the contact member 88 so that the spring tends to hold the contact member in its normal open position. The structure above described is all old and is more fully illustrated in applicant's copending application Serial No. 643,375, filed November 19, 1932.

In order to move the contact member 88 into engagement with the fixed contacts, there is provided a sleeve 88 which is closed at one end, the closed end fitting within a suitable recess in the closure member 88, while projecting therefrom isa stud I88 to which the arm I8 previously mentioned is secured in any desirable manner. This sleeve is provided with slots I82 which embrace the movable contact member 88 when the device is assembled and shoulders I84 are provided on one side of each of these slots for a purpose to be specified later. The closure member 88 may be held in place in any suitable manner, as for instance by tangs extending from the member I2 and bent over the edge oi the member 88, in the manner described in the above mentioned application Serial No. 643,375.

'An internally threaded nut I88 is suitably secured to the shell I6 so as to form a fluid-tight joint therewith and a suitable suction connection is adapted to be threaded into said nut and to extend to the intake manifold in order to communicate the manifold vacuum to the interior of the shell I8. Suitably mounted within the shell I8 and engaging the rounded head I88 oi the member 84 whichis secured to diaphragm I8, is a sheet metal disk I I8 made of suitable material such as steel or bronze for example, which is adapted to be acted upon by the engine vacuum and normally holds the parts in the position shown in Fig. 2 with the contact member 68 in engagement with the inner ace of the closure member 88. The disk II8 exerts a pressure on the head I88 which is sufficient to over-.

come the pressure of a spring I I2 which normally tends to move the contact member 68 away from the face of the closure member 88 and aids the engine suction in bringing about this result when such suction is communicated to the disk II 8.

It will be understood that the disk H8 is preformed by a-pressing operation before assembly into a somewhat concavo-convex shape and when assembled, the slightly convex side of the disk is downward.

- The action of this disk I I8 is very similar to the action of the ordinary manually operable oil can. It normally occupies the position shownin Fig. 2 and when the suction of the engine is communicated to the upper side or such disk, the disk 'will be moved upwardly from theposition shown in Fig. 2. Normally thev disk exerts a considerable degree of pressure tending to hold the parts.

in the position shown in Fig. 2, so much in fact that it requires a suction of substantially tour inches oi. mercury to overcome the normal pressure of the disk and move it from the position the disks! l thereon is relieved.

2,085,889 2 is a relatively weakspring and is only strong enough to move the parts when the pressure of In Fig. 3 is shown a modifledform of the invention in which instead of employing a separate metal diaphragm in addition to that towhich the movable switch contact is connected, such as the diaphragm H0 shown in Fig. 2, the said movable contact may be connected directly to a metal diaphragm preferably of steel and indicated by the ,In other respects the 3 is the same as that and the operation is the sition, such as-shown in Fig. 2, the pressure exerted by the diaphragm tending to hold the movable contact against the face of the member 80 is quite considerable, but as the vacuum increases and approaches a predetermined amount, the downward bow of the disk H0 gives away and thedisk moves with a snap movement and takes a position where the upper face of the disk be- -comesthe bowed facc,,such movement causing opening of the switch contacts. ,It takes a lesser degree of vacuum to hold the disk in this position than to move it-to such position because of .the tendency of thedisk to assume its preformed shape. Eor example, a suction of about a half inch of mercury will hold the disk in position,

while a suction of. b stantially four inches of mercury is necessaryito move the disk as described.

' While the embodimentiof the-present inven tion as herein disclosed, constitutes a preferred form, it is to I might be adopted, all coming within of the claims which follow.

What is claimed is as follows: 1. Control apparatus for an internal combus-' tion engine comprising a starting,motor, a ourthe scope rent source, means for-controlling the connection of the starting motor with the current source in:

' eluding a switch having stationary and movable contacts, suction operated means for causing the disengagement of the'movable contact from the I the engine is running. own power, said suction operated means stationary contact while under its comprising a member adapted to hold saidmovable contact in switch closing position, and means communicating theengine suction. to said memher, said member being deformed by eiiect of the suction thereon to operate said switch and so constructed that the force inherent in the memberitself and exerted by said member in opposithe engine is operating tion to the suction is greater when the switch is in its closed position than its force opposing the effector suction after 'said member has been moved to position to open the switch, whereby during cranking and before starting to 'run under its own power is insufficient to effect opening of the switch, but the suction at any possible operating speed when suflicient to hold the switch open. 2. Control apparatus for an internal combustion engine comprising a starting motor, a' current source, means for controlling the.connection of the starting motor with the current source including a switch having stationary and movable contacts,-and suction operated 'means for causing the disengagement of the movable contactfrom .the stationary contact while the be understood that other forms under its own power is engine is running under its own power, said suction operated means comprising a resilient metallic diaphragm movable to diiferent positions and adapted to effect opening of the switch when moved to one of its, positions, said diaphragm being deformed by the and so constructed that member' itself and exerted by said diaphragm in opposition to the suction is greater when the switch is in its closed position than its force opposing the suction moved to position toopen the switch, whereby th suction of the engine during cranking and before starting to run under its own power is insufficient to effect opening of the switch, but the suction at any possible operating speed when the engine is operating under its own power is 'sufllcient to hold' the switch open:

3. Control apparatus -tion engine comprising a starting motor, a current source, means for controlling the connection of the starting motor with the current source including a switch having stationary and movable contacts, suction operated means for causing the disengagement of the movable contact from the stationary contact while the engine is running under its own power, said suction operated' means comprising a spring steel diaphragm connected to the movable switch contact and adapted to move said contact to open the switch, said diaphragm being suction thereon, 'and so constructed that the force inherent in the. member itself and exerted bysaid' diaphragm in opposition to the suction is greater when the switch is in its closed position than its force opposing the suction after said diaphragm has been moved to position to open the switch, whereby the suction of the engine during cranking and before'starting to run under its own power isinsufflcient to effect opening of the switch, but the suction at any possible operating speed when the engine is operating under its own power is sufficient to hold the switch open.

4. Control apparatus for an internal combusafter said diaphragm has been effect of suction thereon, the force inherent in the for an internal combusdeformed by the action of Y rent source, means for controlling the connection of the starting motor with the current source including a switch having stationary and mov-.

able contacts, and suction operated means for causing the disengagement of the movable contact from the stationary contact while the engine is running under its own power, said suction operated means comprising a concavo-convex spring steel diaphragm connected to and 'nor-,

mally exerting a force tending to hold the switch closed, and adapted. to be moved to open the switch, said diaphragm being deformed by the action of suction thereon, and so constructed that the force inherent in the member itself and-exerted by said diaphragm in opposition to the suction is-greater'when'the switch is in its closed position than its force opposing the suction after said diaphragm has open the switch, whereby the suctionof the engine during cranking and before starting to run under its own power ing'of the switch, but the suction at any possible operating speed when the engine is operating under its own power is sufllcint to holdthe switch open.

' JOHN B. DYER.

been moved to position tois insuflicient to effect open- 

